#!/usr/bin/env bash
# veilor-os installer — TUI wrapper around anaconda kickstart install.
# Runs on tty1 in place of getty (live ISO boot path).
#
# Flow:
#   1. ASCII banner (assets/installer/banner.txt)
#   2. Menu: Install / Live desktop / Live shell / Reboot / Power off
#   3. If Install: collect answers via gum (disk, hostname, LUKS pw,
#      admin pw, locale)
#   4. Generate /run/install/veilor-generated.ks from template + answers
#      (full veilor-os install: package list + overlay + scripts + harden)
#   5. Exec anaconda --kickstart=/run/install/veilor-generated.ks
#   6. On finish: reboot into installed system
#
# v0.5.1 — gum (charm.sh) replaces whiptail; whiptail kept as fallback.
#          Generated kickstart now installs full veilor-os (matches live ks).

set -uo pipefail
export TERM="${TERM:-linux}"
LOG=/var/log/veilor-installer.log

# require_tty MUST run before the tee redirect — process substitution
# replaces fd1 with a pipe, breaking `[[ -t 1 ]]`.
require_tty() {
    if ! [[ -t 0 && -t 1 ]]; then
        echo "[ERR] veilor-installer must run on a real tty" >&2
        exit 1
    fi
}
require_tty

# Now safe to tee output for log persistence — tty detection already passed.
exec > >(tee -a "$LOG") 2>&1

# ── Branded styling for gum ─────────────────────────────────────────────
# colors.gum sets GUM_* env vars — pure-black palette from veilor-black KDE.
# Sourced at top so every prompt below picks up branded colors.
COLORS=/usr/share/veilor-os/assets/installer/colors.gum
[[ -r $COLORS ]] && source "$COLORS"

BANNER_FILE=/usr/share/veilor-os/assets/installer/banner.txt

# Detect TUI backend once. gum is preferred; whiptail is the fallback so the
# installer keeps working on minimal images or if /usr/local/bin/gum is
# missing (e.g. broken vendored binary, /usr remount issues).
if command -v gum >/dev/null 2>&1; then
    TUI=gum
elif command -v whiptail >/dev/null 2>&1; then
    TUI=whiptail
else
    echo "[ERR] neither gum nor whiptail available — cannot run TUI" >&2
    exit 1
fi

banner() {
    clear
    # Read version + date for version line. /etc/os-release has VERSION_ID.
    local ver=""
    [[ -r /etc/os-release ]] && ver=$(. /etc/os-release; echo "${VERSION_ID:-0.0}")
    local d
    d=$(date +%Y-%m-%d)
    local vline="veilor-os ${ver} · ${d} · live"

    if [[ -r $BANNER_FILE ]]; then
        if [[ $TUI == gum ]]; then
            # gum style: rounded border, banner + blank line + version line.
            gum style --border rounded --margin "0 2" --padding "1 3" \
                --border-foreground "${VEILOR_DIM:-240}" \
                --foreground "${VEILOR_FG:-15}" \
                "$(cat "$BANNER_FILE")" \
                "" \
                "$vline"
        else
            cat "$BANNER_FILE"
            echo
            echo "  $vline"
            echo
        fi
    else
        # Fallback ASCII if banner.txt missing (older overlay).
        cat << EOF

   veilor-os installer
   $vline

EOF
    fi
}

# ── TUI wrapper functions ───────────────────────────────────────────────
# Each prompt_* call abstracts gum / whiptail. Always emit the chosen value
# on stdout; non-zero exit on cancel/ESC. Callers use `||` to propagate.

# prompt_choose <header> <opt1> [opt2 ...]
# Single-select menu. Returns the selected option literal on stdout.
prompt_choose() {
    local header=$1; shift
    if [[ $TUI == gum ]]; then
        gum choose --header "$header" "$@"
    else
        # whiptail menu needs tag/desc pairs. Use the option as both.
        local args=()
        local opt
        for opt in "$@"; do args+=("$opt" "$opt"); done
        whiptail --title "veilor-os" --menu "$header" 18 70 8 \
            "${args[@]}" 3>&1 1>&2 2>&3
    fi
}

# prompt_choose_pairs <header> <tag1> <desc1> [tag2 desc2 ...]
# Tag/description menu. Returns the chosen tag.
# Used when display label differs from machine-readable value (e.g. disk
# path /dev/nvme0n1 vs description "476G WDC PC SN740").
prompt_choose_pairs() {
    local header=$1; shift
    if [[ $TUI == gum ]]; then
        # gum has no tag/desc concept — render "tag — desc" lines, parse.
        local lines=() i=1
        while (( i <= $# )); do
            local tag=${!i}; ((i++))
            local desc=${!i}; ((i++))
            lines+=("$tag — $desc")
        done
        local picked
        picked=$(printf '%s\n' "${lines[@]}" | gum choose --header "$header") || return 1
        # Strip " — desc" suffix to recover the tag.
        echo "${picked%% — *}"
    else
        whiptail --title "veilor-os" --menu "$header" 18 70 8 \
            "$@" 3>&1 1>&2 2>&3
    fi
}

# prompt_input <header> [default]
prompt_input() {
    local header=$1 default=${2:-}
    if [[ $TUI == gum ]]; then
        gum input --header "$header" --value "$default"
    else
        whiptail --title "veilor-os" --inputbox "$header" 10 60 "$default" \
            3>&1 1>&2 2>&3
    fi
}

# prompt_password <header>
prompt_password() {
    local header=$1
    if [[ $TUI == gum ]]; then
        gum input --password --header "$header"
    else
        whiptail --title "veilor-os" --passwordbox "$header" 10 60 \
            3>&1 1>&2 2>&3
    fi
}

# prompt_confirm <message>
# Exits 0 on yes, 1 on no — matches whiptail --yesno semantics.
prompt_confirm() {
    local msg=$1
    if [[ $TUI == gum ]]; then
        gum confirm "$msg"
    else
        whiptail --title "Confirm" --yesno "$msg" 16 60
    fi
}

# prompt_message <message>
# Non-blocking notice. gum has no msgbox; print styled + sleep.
prompt_message() {
    local msg=$1
    if [[ $TUI == gum ]]; then
        gum style --foreground "${VEILOR_FG:-15}" --border rounded \
            --border-foreground "${VEILOR_DIM:-240}" --padding "1 2" -- "$msg"
        sleep 2
    else
        whiptail --title "veilor-os" --msgbox "$msg" 10 60
    fi
}

# prompt_error <message>
# Same as message but with a red foreground for visibility.
prompt_error() {
    local msg=$1
    if [[ $TUI == gum ]]; then
        gum style --foreground 1 --border rounded --border-foreground 1 \
            --padding "1 2" -- "$msg"
        sleep 2
    else
        whiptail --title "Error" --msgbox "$msg" 10 60
    fi
}

main_menu() {
    # Empty header — banner already provides context. `──────` line splits
    # primary actions (top) from session controls (bottom). Cursor `❯` set
    # via GUM_CHOOSE_CURSOR in colors.gum.
    prompt_choose "" \
        "Install" \
        "live · KDE" \
        "live · shell" \
        "──────" \
        "Reboot" \
        "Power off"
}

collect_answers() {
    local disk hostname luks_pw admin_pw locale
    local disks_pairs

    # ── Disk ──
    # Build whiptail-style "tag desc" pairs. prompt_choose_pairs reshapes
    # for gum if needed.
    # shellcheck disable=SC2207
    disks_pairs=($(lsblk -dpno NAME,SIZE,MODEL | grep -E '^/dev/(sd|nvme|vd|mmcblk)' | \
        awk '{name=$1; size=$2; $1=""; $2=""; sub(/^ +/,""); gsub(/ /,"_"); model=$0; if(model=="")model="unknown"; print name, size"_"model}'))
    if [[ ${#disks_pairs[@]} -eq 0 ]]; then
        prompt_error "No installable disks found."
        return 1
    fi
    disk=$(prompt_choose_pairs "[1/4] Select install disk · WILL BE ERASED" "${disks_pairs[@]}") || return 1

    # ── Hostname ──
    # Hardcoded for branded consistency. Post-install: `hostnamectl set-hostname`.
    hostname="veilor"

    # Reject shell-special and sed-special chars in passwords. Generated
    # kickstart writes them via heredoc + sed substitution; bare $, ", \, `
    # would corrupt the ks line or partially expand at heredoc time.
    # &, |, /, newline are sed-special: & expands to the matched pattern
    # (so `aA1!@#%^&*()` becomes `aA1!@#%^__ADMIN_PW__*()`), | is our
    # delimiter, / would match if delimiter changes, newline breaks the
    # sed expression. sed_escape() below adds defense-in-depth, but we
    # also reject these at input so the user sees an immediate error
    # rather than a corrupted ks file. 8-char min for entropy.
    validate_pw() {
        local pw=$1 label=$2
        if [[ ${#pw} -lt 8 ]]; then
            prompt_error "Weak $label — minimum 8 characters."
            return 1
        fi
        if [[ $pw =~ [\"\$\\\`\&\|/$'\n'] ]]; then
            prompt_error "Invalid $label — cannot contain: \" \$ \\ \` & | / newline"
            return 1
        fi
        return 0
    }

    # ── LUKS passphrase ──
    luks_pw=$(prompt_password "[2/4] Encryption · LUKS2 passphrase (min 8)") || return 1
    validate_pw "$luks_pw" "passphrase" || return 1

    # ── Admin password ──
    admin_pw=$(prompt_password "[3/4] Admin user · password for 'admin'") || return 1
    validate_pw "$admin_pw" "password" || return 1

    # ── Locale ──
    locale=$(prompt_choose "[4/4] Locale" \
        "en_GB.UTF-8" \
        "en_US.UTF-8") || return 1

    # ── Confirmation ──
    # Render summary box + danger lines via gum style, then gum confirm.
    # Whiptail fallback: simple yesno.
    if [[ $TUI == gum ]]; then
        clear
        gum style --border rounded --margin "1 2" --padding "1 3" \
            --border-foreground "${VEILOR_DIM:-240}" \
            --foreground "${VEILOR_FG:-15}" \
            "Confirm install" \
            "" \
            "  Disk     $disk  $(gum style --foreground 1 'WILL BE ERASED')" \
            "  Locale   $locale" \
            "  LUKS     ✓ set" \
            "  Admin    ✓ set" \
            "" \
            "$(gum style --foreground 3 'This action is irreversible.')"
        gum confirm --affirmative "Yes, install" --negative "Cancel" "Proceed?" || return 1
    else
        whiptail --title "Confirm install" --yesno \
"About to install veilor-os:

  Disk:       $disk (WILL BE ERASED)
  Locale:     $locale
  LUKS:       set
  Admin pw:   set

This action is irreversible.

Proceed?" 16 60 || return 1
    fi

    # Export to caller via globals
    SEL_DISK=$disk
    SEL_HOSTNAME=$hostname
    SEL_LUKS_PW=$luks_pw
    SEL_ADMIN_PW=$admin_pw
    SEL_LOCALE=$locale
    return 0
}

# sed_escape — escape sed special chars in a replacement string.
# Replacement-side metacharacters: & (matched pattern), \ (escape),
# | (our chosen delimiter), / (alternate delimiter — escape too in case
# delimiter ever changes). Newline is rejected in validate_pw because
# escaping it portably across BSD/GNU sed is fiddly.
# Order matters: \ must be escaped FIRST so we don't double-escape the
# backslashes we're about to emit for &, |, /.
sed_escape() {
    printf '%s' "$1" | sed -e 's/[\\&|/]/\\&/g'
}

# detect_seed_pubkey — search attached cdroms for a NoCloud cidata seed
# with an ssh_authorized_keys entry. Returns the first key on stdout, or
# empty string if none found. Used by both auto-install.sh (cloud-init
# seed pre-built with host pubkey) and humans (drop a seed iso next to
# the install media).
detect_seed_pubkey() {
    local dev label tmpmnt key=""
    for dev in /dev/sr0 /dev/sr1 /dev/sr2 /dev/sr3; do
        [ -b "$dev" ] || continue
        label=$(blkid -o value -s LABEL "$dev" 2>/dev/null)
        if [[ $label == "cidata" || $label == "CIDATA" ]]; then
            tmpmnt=$(mktemp -d)
            if mount -o ro "$dev" "$tmpmnt" 2>/dev/null; then
                # NoCloud user-data format:
                #   ssh_authorized_keys:
                #     - ssh-ed25519 AAAA... user@host
                # Extract first ssh-* line, strip leading '- '.
                key=$(grep -E '^\s*-\s+ssh-' "$tmpmnt/user-data" 2>/dev/null \
                    | head -1 | sed -e 's/^\s*-\s*//' -e 's/[[:space:]]*$//')
                umount "$tmpmnt" 2>/dev/null
            fi
            rmdir "$tmpmnt" 2>/dev/null
            [[ -n $key ]] && { printf '%s' "$key"; return 0; }
        fi
    done
    return 1
}

generate_ks() {
    # Build kickstart for actual disk install.
    # NOTE: passwords go in via --plaintext to avoid storing crypted hash
    # collisions; anaconda hashes per /etc/login.defs at install time.
    #
    # %packages mirrors live ks lines 63-141 (full hardening pkg list,
    # minus livesys/anaconda-live which are live-only).
    # %post --nochroot copies overlay + scripts + assets from boot ISO.
    # %post (chroot) runs the same hardening scripts the live build runs.
    local out=/run/install/veilor-generated.ks
    local disk_basename
    disk_basename=$(basename "$SEL_DISK")
    mkdir -p /run/install
    # Single-quoted heredoc → no shell expansion. Substitute placeholders
    # via sed afterwards. Bulletproof against $/`/" in passwords.
    cat > "$out" << 'KSEOF' || return 1
# veilor-os installer-generated kickstart
# DO NOT commit this file — secrets inline.
url --mirrorlist="https://mirrors.fedoraproject.org/mirrorlist?repo=fedora-43&arch=x86_64"
repo --name=fedora --baseurl="https://download.fedoraproject.org/pub/fedora/linux/releases/43/Everything/x86_64/os/" --install
repo --name=updates --baseurl="https://download.fedoraproject.org/pub/fedora/linux/updates/43/Everything/x86_64/" --install

keyboard --xlayouts='us'
lang __LOCALE__
timezone Europe/London --utc

firstboot --disable
eula --agreed
selinux --enforcing
services --enabled=sshd,fail2ban,usbguard,tuned,auditd,firewalld,chronyd,sddm

network --bootproto=dhcp --device=link --activate --hostname=__HOSTNAME__
firewall --enabled --service=ssh

rootpw --lock
user --name=admin --groups=wheel --gecos="veilor admin" --password=__ADMIN_PW__ --plaintext
__SSHKEY_DIRECTIVE__

# Full hardening cmdline (installed system, not live):
# --location=none: anaconda auto-places bootloader (UEFI grub2-efi or BIOS).
bootloader --append="lockdown=integrity slab_nomerge init_on_alloc=1 init_on_free=1 randomize_kstack_offset=on vsyscall=none plymouth.enable=0 rd.plymouth=0"

# Disk: zero, LUKS2 (argon2id), btrfs subvolumes (no LVM intermediary).
# Native btrfs-on-LUKS matches Fedora KDE Spin defaults; LVM+btrfs combo
# triggered "mount failed: wrong fs type, bad option, bad superblock"
# under anaconda --cmdline. btrfs subvols give us the snapshot/rollback
# story without LVM's added complexity.
zerombr
clearpart --all --initlabel --drives=__DISK_BASENAME__
part /boot/efi --fstype=efi --size=600
part /boot --fstype=ext4 --size=1024
part btrfs.veilor --grow --encrypted --luks-version=luks2 --pbkdf=argon2id --passphrase=__LUKS_PW__
btrfs none --label=veilor btrfs.veilor
btrfs / --subvol --name=root LABEL=veilor
btrfs /home --subvol --name=home LABEL=veilor

# ── Packages — mirrors live ks (kickstart/veilor-os.ks 63-141), minus
#    live-only entries (livesys-scripts, anaconda-live, @anaconda-tools,
#    dracut-live, isomd5sum, xorriso) which are pointless on a real disk.
%packages --excludedocs
@^kde-desktop-environment
@kde-apps
@core
@hardware-support
@standard

kernel-modules
kernel-modules-extra
glibc-all-langpacks
dracut-config-generic
kernel
grub2-efi-x64
grub2-efi-x64-modules
grub2-pc
grub2-pc-modules
grub2-tools
grub2-tools-extra
shim-x64
efibootmgr
syslinux

# veilor-installer dependencies (kept on installed system so
# `sudo veilor-installer` from a recovery shell still works).
newt
parted
cryptsetup
lvm2
btrfs-progs

# core hardening tools
fail2ban
fail2ban-firewalld
usbguard
usbguard-tools
audit
policycoreutils-python-utils
tuned
chrony
firewalld
# plymouth: removed in v0.5.13. Splash unreliable in QEMU; LUKS prompt
# falls back to systemd-tty-ask-password-agent on tty1 (text). Cleaner
# boot, smaller initramfs, fewer moving parts.

# admin essentials
git
vim-enhanced
tmux
htop
podman
skopeo
NetworkManager
NetworkManager-wifi

# fonts
fontconfig
freetype
fira-code-fonts

# zram (no swap-on-disk)
zram-generator

# remove fluff
# Note: KDE Plasma 6 hard-deps on cups/geoclue2/ModemManager/PackageKit
# transitively; daemons disabled at runtime via 20-harden-kernel.sh.
-abrt*
-snapd
-kde-connect
-open-vm-tools-desktop
-mlocate
-plymouth
-plymouth-plugin-label
-plymouth-system-theme

%end

# ── Post-install (nochroot): copy overlay + scripts + assets from boot ISO.
# Mirror of live ks 144-196 trimmed to single-source: ISO mounted at
# /run/install/repo, veilor/ subtree contains overlay/, scripts/, assets/.
# (See build/Containerfile — ISO build copies the repo into veilor/.)
%post --nochroot --erroronfail
set -uo pipefail
DEST="${INSTALL_ROOT:-/mnt/sysimage}"
[[ -d $DEST ]] || { echo "[ERR] DEST=$DEST does not exist" >&2; exit 1; }

SRC=/run/install/repo/veilor
if [[ ! -d $SRC/overlay ]]; then
    echo "[ERR] $SRC/overlay missing — boot ISO did not include veilor/ tree" >&2
    exit 1
fi

echo "[INFO] using SRC=$SRC DEST=$DEST"
set -x
cp -a "$SRC/overlay/." "$DEST/" || echo "[ERR] overlay cp failed: $?"
mkdir -p "$DEST/usr/share/veilor-os" || echo "[ERR] mkdir failed: $?"
cp -a "$SRC/assets" "$DEST/usr/share/veilor-os/" || echo "[ERR] assets cp failed: $?"
cp -a "$SRC/scripts" "$DEST/usr/share/veilor-os/" || echo "[ERR] scripts cp failed: $?"
ls -la "$DEST/usr/share/veilor-os/" 2>&1 || echo "[ERR] dest dir missing post-cp"
# Force root ownership on everything we copied — `cp -a` preserves
# CI runner uid (1001), which makes sudo refuse to read /etc/sudoers.d.
chown -R 0:0 "$DEST/etc" "$DEST/usr/share/veilor-os" "$DEST/usr/local/bin" 2>&1 || echo "[WARN] chown failed"
set +x

{
    echo "=== %post --nochroot trace ==="
    date
    echo "SRC=$SRC DEST=$DEST"
    ls -la "$DEST/usr/share/veilor-os/" 2>&1
    ls -la "$DEST/usr/local/bin/" 2>&1
} > "$DEST/var/log/veilor-nochroot.log" 2>&1 || true
%end

# ── Post-install (chroot): apply hardening, theme, branding ────────────
%post
set -uo pipefail
exec > >(tee -a /var/log/veilor-install.log) 2>&1

echo "════════════════════════════════════════════════════════"
echo " veilor-os install — %post (real install)"
echo "════════════════════════════════════════════════════════"

REPO=/usr/share/veilor-os
chmod +x $REPO/scripts/*.sh $REPO/scripts/selinux/*.sh \
    /usr/local/bin/veilor-power /usr/local/bin/veilor-firstboot \
    /usr/local/bin/veilor-installer 2>/dev/null || true

# /etc/machine-id reset on first boot
> /etc/machine-id

# Apply hardening
bash $REPO/scripts/10-harden-base.sh
bash $REPO/scripts/20-harden-kernel.sh

# Build SELinux module
bash $REPO/scripts/selinux/build-policy.sh || echo "[WARN] SELinux build failed; load on first boot"

# Apply KDE theme + DuckSans + os-release branding
bash $REPO/scripts/kde-theme-apply.sh

# Disable plymouth at TWO layers:
#
# 1. Initramfs (the boot stage where LUKS unlock happens). Plymouth is
#    a dracut module; masking units in /etc/systemd/ has zero effect
#    here because dracut bundles its own copies into initramfs/.
#    Solution: omit_dracutmodules in dracut.conf.d, then regenerate
#    initramfs so the new config takes effect.
#
# 2. Real root (post-pivot, before SDDM). /dev/null symlinks mask all
#    plymouth services + the path-activated ask-password unit so they
#    never start when systemd is up.
#
# After both, LUKS prompt falls back to systemd-tty-ask-password-agent
# on tty1 — text "Please enter passphrase for disk... :" — works in
# QEMU sendkey AND on real hardware.

# Layer 1: initramfs
mkdir -p /etc/dracut.conf.d
cat > /etc/dracut.conf.d/99-veilor-no-plymouth.conf << 'EOF'
omit_dracutmodules+=" plymouth "
EOF
# Regenerate initramfs for the installed kernel(s).
for kver in /lib/modules/*/; do
    kver=$(basename "$kver")
    dracut --force --kver "$kver" 2>/dev/null || true
done

# Layer 2: real-root masks
mkdir -p /etc/systemd/system
for unit in \
    plymouth-start.service \
    plymouth-quit.service \
    plymouth-quit-wait.service \
    plymouth-read-write.service \
    plymouth-switch-root.service \
    systemd-ask-password-plymouth.path \
    systemd-ask-password-plymouth.service \
    ; do
    ln -sf /dev/null /etc/systemd/system/$unit
done

# Symlink display-manager.service → sddm.service. (Anaconda usually
# handles this when sddm is the only DM, but be explicit.)
ln -sf /usr/lib/systemd/system/sddm.service /etc/systemd/system/display-manager.service

# Real install boots straight to SDDM (NOT to TTY1 installer like live).
systemctl set-default graphical.target

# zram swap (no disk swap; keys never leak to platter)
cat > /etc/systemd/zram-generator.conf << 'EOF'
[zram0]
zram-size = min(ram, 8192)
compression-algorithm = zstd
EOF

# Enable services
systemctl enable veilor-firstboot.service 2>/dev/null || true
systemctl enable veilor-modules-lock.service 2>/dev/null || true
systemctl enable sshd fail2ban usbguard tuned auditd firewalld chronyd sddm

# Default tuned profile = balanced (AC/battery udev rule will override)
tuned-adm profile veilor-balanced 2>/dev/null || true

# Force admin to set a fresh password on first login. The `user` directive
# above already created the account with the user's chosen password —
# `chage -d 0` expires it so SDDM/passwd prompts for change immediately.
chage -d 0 admin 2>/dev/null || true

# Lock root explicitly (kickstart --lock should already do this)
passwd -l root

# Sanity: zero references to onyx / personal IPs in installed system
if grep -rqi 'onyx\|192\.168\.0\.\|fedora\.local' /etc/veilor* /etc/tuned/profiles/veilor-* 2>/dev/null; then
    echo "[ERR] brand leak detected in /etc — investigate"
fi

echo "════════════════════════════════════════════════════════"
echo " veilor-os install complete"
echo "════════════════════════════════════════════════════════"
%end

# Reboot when done
reboot
KSEOF
    # Substitute placeholders. Use | as sed delimiter. validate_pw()
    # already rejects "$\`&|/\n at input — sed_escape() is defence in
    # depth in case future code paths feed unsanitised values (e.g.
    # locale/hostname from a file, or a relaxed validator).
    # Detect cloud-init seed pubkey (if attached) → embed as anaconda
    # `sshkey --username=admin` directive. Adds key to admin's
    # authorized_keys at install time so SSH validation works first boot.
    # No seed = empty directive line (anaconda treats blank line as no-op).
    local seed_pubkey sshkey_directive=""
    seed_pubkey=$(detect_seed_pubkey 2>/dev/null) || true
    if [[ -n $seed_pubkey ]]; then
        echo "[INFO] using cloud-init seed pubkey for admin authorized_keys"
        # sshkey directive — quote pubkey, no shell meta in pubkeys.
        sshkey_directive="sshkey --username=admin \"${seed_pubkey}\""
    fi

    sed -i \
        -e "s|__LOCALE__|$(sed_escape "$SEL_LOCALE")|" \
        -e "s|__HOSTNAME__|$(sed_escape "$SEL_HOSTNAME")|" \
        -e "s|__DISK_BASENAME__|$(sed_escape "$disk_basename")|" \
        -e "s|__LUKS_PW__|$(sed_escape "$SEL_LUKS_PW")|" \
        -e "s|__ADMIN_PW__|$(sed_escape "$SEL_ADMIN_PW")|" \
        -e "s|__SSHKEY_DIRECTIVE__|$(sed_escape "$sshkey_directive")|" \
        "$out"
    echo "[INFO] generated kickstart at $out"
    return 0
}

run_install() {
    # Anaconda env setup (see comments below).
    export LANG="${SEL_LOCALE:-en_GB.UTF-8}"
    export LC_ALL="$LANG"
    # LANG / LC_ALL: anaconda's keyboard.activate_keyboard() raises
    # AnacondaError: 'LANG' if missing. tty1 inherits no locale by default.
    # XDG_RUNTIME_DIR: anaconda's display.setup_display() probes
    # os.getenv("XDG_RUNTIME_DIR") + Wayland socket and crashes with
    # TypeError on None. We're running unattended so no display needed,
    # but env var still has to exist.
    export XDG_RUNTIME_DIR="/run/user/$(id -u)"
    mkdir -p "$XDG_RUNTIME_DIR"
    chmod 0700 "$XDG_RUNTIME_DIR"

    if [[ $TUI == gum ]]; then
        clear
        # gum spin runs anaconda as subprocess. --show-output forwards
        # stdout/stderr to /tmp/anaconda-cmdline.log so we can debug.
        # --title shows live-updating header. --spinner dot is minimal.
        local rc=0
        gum spin --spinner dot \
            --title "Installing veilor-os to $SEL_DISK · this takes 10-30 min · logs on tty2" \
            --show-output \
            -- bash -c 'anaconda --cmdline --kickstart=/run/install/veilor-generated.ks 2>&1 | tee /tmp/anaconda-cmdline.log' || rc=$?
        if [[ $rc -eq 0 ]]; then
            gum style --foreground 2 --border rounded --margin "1 2" --padding "1 3" \
                "✓ Install complete" \
                "" \
                "System will reboot in 5 seconds." \
                "Remove the install media."
            sleep 5
            systemctl reboot
        else
            prompt_error "Anaconda exited non-zero (status $rc).
Logs at /tmp/anaconda.log + /var/log/veilor-installer.log.
Press OK to drop to shell."
            return 1
        fi
    else
        prompt_message "Installing veilor-os to $SEL_DISK ...
This will take 10-30 minutes.
Logs: /var/log/veilor-installer.log + /tmp/anaconda.log"
        sleep 1
        if anaconda --cmdline --kickstart=/run/install/veilor-generated.ks; then
            prompt_message "Install complete. System will reboot.
Remove the install media after shutdown."
            sleep 3
            systemctl reboot
        else
            prompt_error "Anaconda exited non-zero.
Logs at /tmp/anaconda.log + /var/log/veilor-installer.log.
Press OK to drop to shell."
            return 1
        fi
    fi
}

drop_to_shell() {
    clear
    cat << 'EOF'
═══════════════════════════════════════════════════
 veilor-os live shell
═══════════════════════════════════════════════════

You are in a live, in-memory environment.
Nothing persists across reboot.

Re-run the installer:    sudo veilor-installer
Reboot:                  sudo systemctl reboot
Power off:               sudo systemctl poweroff

EOF
    exec /bin/bash --login
}

launch_desktop() {
    clear
    echo "Launching KDE Plasma..."
    sleep 1
    systemctl isolate graphical.target
    # systemd-isolate switches target; sddm spawns on tty1.
    # If user logs out, they come back here. Loop continues.
}

# ── Entry ──
# (require_tty already called above before exec redirect — see top of file)
banner

while true; do
    case "$(main_menu)" in
        "Install")
            if collect_answers && generate_ks; then
                run_install || continue
            fi
            ;;
        "live · KDE") launch_desktop ;;
        "live · shell") drop_to_shell ;;
        "──────") banner ;;  # separator clicked: redraw, no-op
        "Reboot") systemctl reboot ;;
        "Power off") systemctl poweroff ;;
        "") banner ;;  # ESC/cancel from menu: redraw
        *) banner ;;
    esac
done